1. Field of the Invention
This invention relates generally to magnetic recording hard disk drives (HDDs), and more particularly to a HDD that is operable in environments where track misregistration (TMR) of the write head occurs.
2. Description of the Related Art
HDDs with high data density are required to have high data track density, which means that the concentric data tracks are packed closer together. High track density increases the problem of adjacent track encroachment of the write field from the write head if the write head is not precisely located on the target data track during writing. This track misregistration (TMR) can cause overwriting (erasure) of data in adjacent tracks, which results in unrecoverable data when the data on the adjacent tracks is attempted to be read back later. One prior art solution is to place the data tracks farther apart, i.e., increase the track pitch. However, this decreases the overall data density of the disk drive. Another solution is to inhibit writing whenever the disk drive's servo control electronics detects that TMR has occurred or is about to occur. However, in a high TMR environment this may cause write inhibit to be continuously enabled, thereby degrading performance of the disk drive.
What is needed is a HDD with increased data track density that remains operational even in high TMR environments.